Abstract : An optical telecommunication network is configured to transmit a given trafficin order to meet a given objective. However the demand changes with time andinfrastructure development. The reconfiguration problem stands in thiscontext. It consists in being able to alter the configuration of the networkto adjust it to the new traffic. It is generally necessary to interruptpartially or totally the traffic to reconfigure a network. Considering theamount of data flowing on it, it may not be possible to regularly stop thenetwork, even for a short amount of time. Many parameters have to be takeninto account to find out a good solution, and many metrics can be used inorder to measure the quality of a solution.

In a first part, we focus on the reconfiguration problem as a mono-objectiveoptimization problem. We propose a mathematical model representing thereconfiguration problem. However solving exactly the proposed model mayrequire a high computational time. We also propose a greedy and a simulatedannealing heuristics. Depending on the metric optimized, the solutions havedifferent characteristics. The greedy algorithm is fast and provides decentsolutions whereas the simulated annealing algorithm provides solutionscompeting with the optimal ones.

In a second part, we focus on the multiobjective aspect of the reconfigurationproblem. We consider at the same time different metrics and search for a setof solutions representing different interesting trade-offs instead of a uniquesolution. We propose an algorithm based on our mathematical formulation. Wealso adapt an evolutionary algorithm. The proposed methods succeed in findingdifferent interesting trade-offs. Giving a little flexibility with respect toa metric generally allows to significantly improve the solutions with respectto the other metrics.